1. Field of the Invention
This invention pertains generally to the field of debris collection, and more specifically to a collector for airborne debris.
2. Description of the Related Art
Portable power tools greatly facilitate many tasks, including both fabrication and repair. For exemplary purposes, a power hand grinder may be used to remove material or cut through metal in a very small fraction of the time required to complete the same task manually. The particular power source used to power the tool is not important for the present invention, and is known to include such diverse sources as compressed air, electricity, internal combustion engines, and other suitable sources.
These portable power tools have been devised for many tasks, some which are known to rapidly expel large amounts of fine debris into the air. Exemplary processes are abrasive, such as sanding and grinding operations, though there are other operations as well which release debris into the air. In addition, there exist a number of additional procedures and processes that do not use power tools, but which also produce undesirable airborne particulates. Exemplary of such additional processes are painting and particulate blasting, both which often also produce fine particulate airborne contaminants.
These particles can remain suspended in the air momentarily, or even for relatively substantial time periods, depending upon the particle size and composition, and air currents. These particles, sometimes referred to as particulates, literally create a dust cloud. Even after settling out of the air onto surfaces, the fine particles are readily disturbed and re-introduced into the air, such as by a breeze through an open door or window, by movement of a person or work object, or by another work process.
Such dust can be inhaled or settle on the skin, causing irritation or constituting a respiratory and/or health hazard for individuals in the immediate vicinity. Exposure to dust in coal mines has long been known to result in black lung disease, and more recently exposure to asbestos, silica, and other compounds has also been directly linked to specific diseases and morbidity or mortality. Furthermore, such dust can accumulate on tools, causing premature aging and failure of the tools, and on surfaces such as work areas or objects being worked upon, potentially contaminating work areas or disturbing the appearance of the work. For exemplary purposes, dust produced in an automotive repair shop from grinding, brushing, or other similar processes may foul the air within the shop. Not only will the shop workers be undesirably exposed to the dust, the automobiles being repaired will likewise be coated with the dust.
Currently, the problem of power tool and similar dust is handled in several different ways. One such approach is to create a ventilated space, as in U.S. Pat. Nos. 2,247,891 and 2,292,665 by Schneible, entitled “Ventilating Apparatus.” This system provides directed, relatively even or laminar flow across an open space such as a room or chamber. To be beneficial, the work operation must be conducted within the room or chamber. As will be apparent, one benefit of portable tools is the ability to bring the tool to the work. The work desirably may not be within a predetermined room or chamber.
A similar approach is to use a dust hood for machines, a variety of which are illustrated in U.S. Pat. Nos. 2,565,510 by Martin, entitled “Dust Collector for Tile Cutting Machines and the Like”; 2,667,017 by Jaron, entitled “Dust Collector Hood Construction”; 3,945,281 by Kreitz, entitled “Dust Collector for Radial Arm Saws”; 5,074,198 by Aalto et al, entitled “Focussed Ventilation Procedure for a Work Spot and Apparatus Used in the Procedure”; 5,594,972 and 5,941,766 by Iversen, entitled “Dust Collector” and 6,159,086 by McClurkin, entitled “Dust Collecting Work Station.” These relatively large hoods interfere with the portable nature of the tool, and prevent all but the most basic of manipulation. As a result, these collectors are found almost exclusively only on “bench” machines which are affixed to the bench or another stand, and are therefore not hand-manipulable except through basic, predetermined movements. In addition, the prior art has not adequately controlled air flow in these large hoods, resulting in a large portion of the hood being prone to particulates bouncing off of or otherwise escaping from the hood.
Others yet have chosen to go straight to the source and have implemented vacuums into tools. Exemplary of these are U.S. Pat. Nos. 2,499,933 by Smul, entitled “Surface Cleaning Attachment”; 4,759,155 by Shaw, entitled “Particle Collecting Sander”; 5,125,190 by Buser et al, entitled “Dust Collector and Shield for Rotary Grinder”; 5,220,753 by Whitman, entitled “Safety Vacuum Shield for Flexible Cable and Motor Tool”; and 5,931,072 by Shibata, entitled “Circular Saw with an Improved Dust Collector”. These dust collectors suffer from two opposing challenges. The first challenge arises from the operating speed of the machine or tool. Fine dust which remains suspended for long time periods is often produced by abrasive machines which operate at higher speeds. Unfortunately, this also means that the particles ejected therefrom are ejected at great velocities, and may be entrained in a high velocity air stream produced by the abrasive tool. To be effective, the vacuum must draw this air or particulate stream into an inlet. Unfortunately, the exact direction of the stream is often dependent upon the angle of contact between tool and work. Consequently, a larger collector is desirable to ensure collection of the high velocity stream being emitted from the work.
The second challenge arises when the tool is portable. The dust collector necessarily interferes with the portable nature of the tool. This interference arises from the additional bulk required for the collector, but perhaps more importantly, also arises from a desire for efficiency of collection to couple the collector to a vacuum source. This additional hosing can greatly interfere with proficient manipulation of the tool. Consequently, it is desirable to produce a smaller, more compact dust collector that is uncoupled from any other device to maintain the portable nature of the tool. A small collector is less likely to capture particulate, and, without a hose coupled to a vacuum source, a collection bag or the like blocks flow and rapidly clogs. Trying to maintain a small, uncoupled dust collector necessarily renders the dust collector substantially less effective than is desirable for most work environments. These collectors are useful and beneficial, but not adequate for most work environments.
U.S. Pat. Nos. 3,525,183 by Gargrave, entitled “Dust Collector” and 7,189,272 by Cheng, entitled “Movable Spray Painting Stand” illustrate portable dust collectors, enabling use in any variety of work spaces and with a variety of tools or particulate generators. While more universal, these patents suffer from the drawbacks associated with the tool-specific hoods described herein above.
Each of the foregoing patents are incorporated herein by reference for their illustrations and teachings relevant to the present invention, though they each lack certain deficiencies found in the present invention that are desirable in the art and enumerated herein below. Webster's New Universal Unabridged Dictionary, Second Edition copyright 1983, is additionally incorporated herein by reference in entirety for the definitions of words and terms used herein.